Disazo dyes for wool.



' cooled with ice.

,UNTTED v STATEES PATENT @FFTQE.

AUGUST LEOPOLD LASKA, OF OFFENBACI-I-ON-THE-MAIN, GERMANY, ASSIGNOR, TO THE CORPORATION OF CHEMISGHE FABRIK GRIESHEIM-ELEKTBON, O13 FBANKFORT-ON- DISAZO DYES FOB, WOOL.

No Drawing.

To all whom "it may concern:

Be it known that I, AUGUST LEoPoLo LASKA, doctor of philosophy, chemist, a subject of the German Emperor, and resident of Ofitenbach-on-the Main, in the Grand Duchy of Hessen, Germany, with the postofiice address Gerberstrasse No. 5, have in Vented new and useful Improvements in Disazo Dyes for ool, of which the following is a specification.

My invention relates to the manufacture of disazo dyestuffs for wool and consists in combining tetrazotized diaminobases of the I V 1 dichlorobenzidin are dissolved in 500 parts of water and 45 parts of hydrochloric acid 20 B., cooled with ice and diazotized with V a solution of 7 parts of sodium nitrite.

general formula wherein X means CH or Cl with one molecular proportion of an ortho-oxy-carboxylic acid of the benzene series and 111 alkaline solution with one molecular proportion of a 2zamino-8-naphthol compound of the general formula:

l l w/V wherein R means H or a substituent, for instance an alkyl, an aralkylor an aryl group. The thus obtained dyestuffs dye wool from acid bath from redd1sh to yellowish'brown shades, which in the m lling process without after treatment w th chromates do not stain interwoven white wool and cotton.

Diaminobases of the aforesaid constitution are meta-tolidin and meta-meta dichlorobenzidin.

The following examples will serve to illustrate the nature of my invention and how it can be carried out; parts being by Weight.

Example I: 10.6 parts of meta-tolidin are tetrazotized in the usual manner. The tetrazo compound is poured into a solution of 7 .5 parts of salicylic acid containing the necessary amount of sodium carbonate and After formation of the intermediate product a solution of 16 parts of 2 phenylamino 8 naphthol 6 sulfonic acid, neutralized by means of sodium carbonate, is added. The mixture is stirred of-water cooled with ice.

Specification of Letters Patent. Patented J 11119 13, 1911,

Application ifiled December 13, 1910. Serial No. 597,083.

. during 12 hours, and the dyestuff finished in the usual manner. t is in dry state a dark-brown powder, soluble in concentrated sulfuric acid with red-brown, in water with brown color. The aqueous solution turns rather reddish by addition of caustic soda lye; by addition of hydrochloric acid the dyestuff is precipitated in shape of redbrown flakes. 1t dyes wool from acid bath yellowish-brown shades, which do not stain interwoven white wool and cotton in the milling process.

Example 11: 12.65 parts of meta-meta The tetrazo compound. is allowed to flow into a solution of 7.5 parts of salicylic acid and 55 parts of sodium carbonate in 500 parts After formation of the intermediate product a solution of 16 parts of 2 phenylamino 8 naphthol 6- sulfonic acid neutralized by means of soda, is added, and the mixture stirred durlng 12 hours. The dyestufi is finished in the usual It is in dry state a brown-black powder, soluble in concentrated sulfuric acid with red-brown, in water with brown color.

The aqueous solution is hardly altered by addition of caustic soda lye; by addition of hydrochloric acid the dyestufl is precipitated in shape of brown flakes. It dyes wool from acid bath yellowish-brown shades' of good fastness to milling.

In the same manner may be performed the manufacture of dyestufi if instead of salicylic acid orthoor meta-cresotinic acid, and instead of 2-phenylamino-8-naphthol-6-sulfonic acid other arylized or alkylized derivatives of the 2-amino-8-naphthol-6-sulfonic acid or the 2amino-8-11aphthol-6-sulfonic acid itself are used.

All the thus obtained dyestuffs show the same essential properties; they dye wool brown shades which in the millin process do not stain interwoven white woof and cotton.

Now what I claim and desire to secure by Letters Patent is the following:

1. The process for manufacturing brown azo dyestuffs for W001, consisting in combin ing the tetrazo compounds of diaminobases with one molecular proportion of an orthooxy-carboxylic acid of the benzene series, and

in alkaline solution with one molecular proportion of 2 arylamino 8 naphthol-(i-sulfonic acid.

2. The process for the manufacture of brown azo dyestuffs for W001 consisting in combining the tetrazo compounds of metameta -dichlorobenzidin with one molecular proportion of an ortho-oXy-carboXylic acid of the benzene series, and in alkaline solution with one molecular proportion of 2- arylamino8-naphthol-6-sulfonic acid.

3. As new articles the azo dyestufis obtained by combining the tetrazo compound of metameta- -dichlorobenzidin with one molecular proportion of an ortho-oXy-carboxylic acid of the benzene series, and in alkaline solution with one molecular proportion of 2-arylamino-S-naphthol-6-sulfonic acid, which dyestuffs are dark brown powders, soluble in concentrated sulfuric acid with red-brown, in water with brown color, the aqueous solution being hardly altered by addition of caustic soda lye, the dyestuffs being precipitated thereof by addition of hydrochloric acid in shape of red-brown flakes dyeing wool brown shades fast to milling, yielding upon reduction with stannous chloricl and hydrochloric acid metameta dichlorobenzidin, a p amino orthooxy-carboxylic acid of the benzene series and 7 amino 2-arylamino-S-naphthol-G-sulfonic acid.

4. The process for manufacturing a brown azo dyestuff for W001, consisting in combining the tetrazo compound of meta-meta dichlorobenzidin with one molecular propor tion of salicylic acid, and in alkaline solution with one molecular proportion of 2- phenylamino-8-naphthol-6-sulfonic acid.

5. As a new article the azo dyestuff, obtained by combining the tetra compound of meta-meta -dichlorobenzidin with one molecular proportion of salicylic acid, and in alkaline solution with one molecular proportion of 2-phenyl amino-S-naphthol 6 sulfonic acid, which dyestuif is a dark brown powder, soluble in concentrated sulfuric acid with red-brown, in water with brown color, the aqueous solution turning rather more red by addition of caustic soda lye, the dyestuif being precipitated thereof by addition of hydrochloric acid in shape of red-brown flakes and dyeing wool brown shades fast to milling, yielding upon reduction with stannous chlorid and hydrochloric acid meta-meta -dichlorobenzidin, p amino-salicylic acid and 7 amino-2-phenylamino-8- naphthol-6sulfonic acid.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two witnesses, this second day of December 1910.

AUGUST LEOPOLD LASKA. lVitnesses:

HERMANN WEIL, EMMA MARX.

' Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. C. 

